The parents of a baby who they believe may have been targetted by Lucy Letby have recalled their chilling interaction with the serial killer – as they spoke out for the first time in a new documentary.

Letby, a former nurse at the Countess Of Chester Hospital, is currently serving 15 whole-life sentences having been convicted of murdering seven infants and attempting to murder seven others, and is Britain’s worst serial killer in modern times.

Judges have refused to grant her an appeal against her conviction, meaning she will die in prison – however, a campaign to clear Letby, alleging a miscarriage of justice, has begun to gain traction

A new documentary on Channel 4Lucy Letby: Murder Or Mistake, heard for the first time from the parents of a baby who was born in the Countess Of Chester Hospital in 2015, while Letby was on duty as a nurse.

Speaking anonymously on the show, which airs tonight, they recalled their first interaction with the nurse – and how they immediately realised her behaviour ‘wasn’t normal’.

The parents, who have ‘never gone public’ with what happened to them until now, said their baby son was born perfectly healthy, and had been ‘healthy the whole way through the pregnancy’, until he was suddenly taken away by staff, who said he ‘needed a bit of help breathing’.

They described their excruciating worry when he wasn’t returned to them ‘for a couple of hours’.

It was then that they encountered Letby for the first time while they were waiting for news of their son, as she came to them to offer them a ‘box’ – with no update or information on their baby.

The parents of a baby who they believe was an attempted murder victim of Lucy Letby have recalled their chilling interaction with the serial killer

The mother said she immediately ‘burst into tears’, thinking the worst, and desperately asking Letby if her child was dead.

Chillingly, she said that Letby ‘just laughed’ – a reaction that has stayed with her over the years.

The mother said: ‘I burst into tears. I remember saying to her, “Oh my god, is he dead”.

‘And she just laughed. She was laughing when she thought we thought the worst had happened.

‘She said, “We just give these boxes to parents who have been really poorly”.’

A doctor explained that the nursing staff couldn’t work out what the issue was and eventually advised them to take their son to Liverpool Women’s Hospital instead – a decision the parents credit with ‘saving his life’.

Though the parents have not specified more details about their child in relation to Letby, they believe the nurse had attempted to kill him – and that the decision to remove him from Letby’s care saved him.

The mother added: ‘That decision is what saved him, I think, and we’ll always be grateful to that doctor for that.

Speaking anonymously in a new Channel 4 documentary, which airs tonight, the couple recalled their first interaction with the nurse – and how they immediately realised her behaviour ‘wasn’t normal’

Letby handed them a blue box after their son was taken away from them – and merely ‘laughed’ when they asked if their son had died

‘It was only when we saw her face in the newspaper later on, that we both recognised her straight away. The nurse that gave us the box was Lucy Letby.’

Later, when the parents opened the box, they found a wrist strap, a baby hat, a blanket and a notepad that Letby told them they could use as a diary.

‘I think if something like the box had been given later on, after we’d seen him, it might have been different,’ the mother said.

‘But at that point in time, to come in and laugh, it was just not normal. It’s just too much.’

They added that while their son was ‘fine’ when he was smaller, ‘issues’ started to emerge from the age of five.

Their son has education delay by around two years, and still can’t write well. He also suffers from regular seizures, including ones that ‘haven’t stopped for 15 to 20 minutes’.

His mother explained: ‘He’ll ask us, if he has a fit, will he die. All weekend, he kept saying to me, “I wish I was normal, I wish I was normal.” He just wants to be like everyone else.’

Chillingly, after seeing his parents’ reactions to Letby’s conviction on TV, their son asked: ‘Is that the naughty nurse that tried to kill me?’

Letby is pictured being arrested at her home in Chester on July 3, 2018

Both sides of the case are explored thoroughly in the Channel 4 documentary, which hears evidence from Dr Dewi Evans, the prosecution’s expert witness, who played a major role in the trial determining the guilty verdict.

It also hears from Daily Mail journalist Liz Hull, who sat through both her trials.

On the other side of the case is Letby’s barrister Mark McDonald, who is planning a fresh appeal on behalf of his client.

‘I have a client that says they are innocent. They have a conviction for murder,’ he explained.

‘There’s always a pattern in these cases, that nurse was always on duty. There are four nurses currently in prison, serving life for these type of offences.

‘From the moment she was arrested, I knew how it was going to play out. I could have written the prosecution speech. It was textbook.’

McDonald is applying to the Criminal Cases Review Commission (CCRC) in the hope it can be returned to the Court Of Appeal with new evidence.

In an interview this morning, Letby’s barrister Mark McDonald, who appears in the documentary, said he has 26 separate experts and 1,000 pages of fresh evidence to back up his claim

In the show, McDonald speaks to neonatologists Dr Neil Acton and Dr Svilena Dimitrova to discuss the case of Baby O, who was found by the prosecution to be the first infant murdered by Letby in June 2016.

One of identical triplets, Baby O had no concerns when Letby began her shift, but a few hours later, had started to collapse and deteriorate. A few hours after that, he collapsed for a second time and tragically passed away.

However, Dr Acton and Dr Dimitrova alleged that two medical reviews did not pick up on changes that had happened overnight – which they say was an oversight.

In addition, during a resuscitation attempt, they said a consultant put a needle into the baby’s diaphragm to dilate it, which caused damage and bleeding.

McDonald said: ‘The two experts say, no crime was committed. If they are right, then LL did not harm this child.’

McDonald said he has 26 separate experts and 1,000 pages of fresh evidence to back up his claim that Letby is innocent.

The barrister says he has now passed on this evidence to the CCRC in the hope of getting the former neonatal nurse released.

Appearing on Good Morning Britain on Monday, he said: ‘I was instructed a year ago this week.

‘There is obviously a concern here among experts that something is seriously wrong.

‘A year ago when I went to see her she had lost everything and she said no one believed her, she was a broken woman.

‘Now seeing these experts saying no crime was committed she has hope.’

Since she was jailed for killing seven babies in a year-long reign of terror that shocked the nation, there has been a furious debate over whether the evidence against her was flawed, with a growing body of supporters arguing she is innocent.

Earlier this year, medical experts reviewing her convictions claimed they ‘did not find any murders’ amid questions over evidence used to convict the child serial killer.

Her trial at Manchester Crown Court had heard the babies were attacked between 2015 and 2016 while she worked at the Countess of Chester Hospital’s neonatal unit.

According to the BBC, babies suffered potentially life-threatening incidents on almost a third of the 33 shifts Letby was on duty while training at the Trust.

In one case, from November 2012, a baby boy she was caring for collapsed and water was later discovered in his breathing tube, which experts say is highly irregular.

Dr Dewi Evans, the former lead prosecution witness at Letby’s original trial, also previously told the Mail he had concerns over the deaths of at least three children and the collapses of as many as 15 more, including one potentially poisoned with insulin, all of which were not included on the original indictment.

He said he had suspicions that Letby experimented with moving babies’ breathing tubes as a method of causing harm before she began injecting air into their bloodstreams, or into their tummies via their nasal feeding tubes in a bid to kill.

‘One thing we can be reasonably sure of is that Lucy Letby did not turn up to work one day and decide to inject a baby with air into their bloodstream,’ Dr Evans said. ‘I think the modus operandi evolved over time and I think that prior to air embolus tube displacement was probably something that she did.’

Lucy Letby: Murder Or Mistake airs on Channel 4 on Monday at 9pm. Part two of the documentary follows at 10pm.